| From 9e432f0b7ae9f76328a714555be82f6963297f89 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 11 Aug 2023 11:26:30 +0100 |
| Subject: net: phy: fix IRQ-based wake-on-lan over hibernate / power off |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> |
| |
| [ Upstream commit cc941e548bffc01b5816b4edc5cb432a137a58b3 ] |
| |
| Uwe reports: |
| "Most PHYs signal WoL using an interrupt. So disabling interrupts [at |
| shutdown] breaks WoL at least on PHYs covered by the marvell driver." |
| |
| Discussing with Ioana, the problem which was trying to be solved was: |
| "The board in question is a LS1021ATSN which has two AR8031 PHYs that |
| share an interrupt line. In case only one of the PHYs is probed and |
| there are pending interrupts on the PHY#2 an IRQ storm will happen |
| since there is no entity to clear the interrupt from PHY#2's registers. |
| PHY#1's driver will get stuck in .handle_interrupt() indefinitely." |
| |
| Further confirmation that "the two AR8031 PHYs are on the same MDIO |
| bus." |
| |
| With WoL using interrupts to wake the system, in such a case, the |
| system will begin booting with an asserted interrupt. Thus, we need to |
| cope with an interrupt asserted during boot. |
| |
| Solve this instead by disabling interrupts during PHY probe. This will |
| ensure in Ioana's situation that both PHYs of the same type sharing an |
| interrupt line on a common MDIO bus will have their interrupt outputs |
| disabled when the driver probes the device, but before we hook in any |
| interrupt handlers - thus avoiding the interrupt storm. |
| |
| A better fix would be for platform firmware to disable the interrupting |
| devices at source during boot, before control is handed to the kernel. |
| |
| Fixes: e2f016cf7751 ("net: phy: add a shutdown procedure") |
| Link: 20230804071757.383971-1-u.kleine-koenig@pengutronix.de |
| Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
| Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> |
| Reviewed-by: Andrew Lunn <andrew@lunn.ch> |
| Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/phy/phy_device.c | 13 ++----------- |
| 1 file changed, 2 insertions(+), 11 deletions(-) |
| |
| diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c |
| index 6085a28cae3d2..0429825a7179d 100644 |
| --- a/drivers/net/phy/phy_device.c |
| +++ b/drivers/net/phy/phy_device.c |
| @@ -3061,6 +3061,8 @@ static int phy_probe(struct device *dev) |
| goto out; |
| } |
| |
| + phy_disable_interrupts(phydev); |
| + |
| /* Start out supporting everything. Eventually, |
| * a controller will attach, and may modify one |
| * or both of these values |
| @@ -3148,16 +3150,6 @@ static int phy_remove(struct device *dev) |
| return 0; |
| } |
| |
| -static void phy_shutdown(struct device *dev) |
| -{ |
| - struct phy_device *phydev = to_phy_device(dev); |
| - |
| - if (phydev->state == PHY_READY || !phydev->attached_dev) |
| - return; |
| - |
| - phy_disable_interrupts(phydev); |
| -} |
| - |
| /** |
| * phy_driver_register - register a phy_driver with the PHY layer |
| * @new_driver: new phy_driver to register |
| @@ -3181,7 +3173,6 @@ int phy_driver_register(struct phy_driver *new_driver, struct module *owner) |
| new_driver->mdiodrv.driver.bus = &mdio_bus_type; |
| new_driver->mdiodrv.driver.probe = phy_probe; |
| new_driver->mdiodrv.driver.remove = phy_remove; |
| - new_driver->mdiodrv.driver.shutdown = phy_shutdown; |
| new_driver->mdiodrv.driver.owner = owner; |
| new_driver->mdiodrv.driver.probe_type = PROBE_FORCE_SYNCHRONOUS; |
| |
| -- |
| 2.40.1 |
| |
